```js
// addon-toolbar/register.js

import React from "react";

import addons, { types } from "@storybook/addons";

import { Icons, IconButton } from '@storybook/components';

addons.register("my/toolbar", () => {
  addons.add("my-toolbar-addon/toolbar", {
    title: "Example Storybook toolbar",
    //👇 Sets the type of UI element in Storybook
    type: types.TOOL,
    //👇 Shows the Toolbar UI element if either the Canvas or Docs tab is active
    match: ({ viewMode }) => !!(viewMode && viewMode.match(/^(story|docs)$/)),
    render: ({ active }) => (
      <IconButton
        active={active}
        title="Show a Storybook toolbar"
      >
        <Icons icon="outline" />
      </IconButton>
    ),
  });
});
```